MongoDB数据库(一):基本操作
1.NoSQL的概念
"NoSQL"一词最早于1998年被用于一个轻量级的关系数据库的名字
随着web2.0的快速发展,NoSQL概念在2009年被提了出来
NoSQL最常见的解释是"non-relational","Not Only SQL"也被很多人接受,指的是非关系型数据库
2.关系型数据库和非关系型的区别
关系型数据库很强大,但是并不能很好的应付所有的场景.关系型数据库的扩展性差,大数据下IO压力大,表结构更改困难
非关系型数据库易扩展,大数据量高性能,灵活的数据模型,高可用
3.MongoDB数据库的优势
- 易扩展:去掉关系型数据库的关系型特性,数据之间无关系,非常容易扩展
- 大数据量,高性能:得益于无关系性,数据库的结构简单,有非常高的读写性能,尤其是在大数据量下,同样表现优秀
- 灵活的数据模型:无需事先为要存储的数据建立字段,随时可以存储自定义的数据格式
4.安装及启动MongoDB数据库
4.1 安装EPEL源
[root@localhost ~]# yum list | grep epel
epel-release.noarch 7-11 @extras
htop.x86_64 2.2.0-3.el7 @epel
libdb4.x86_64 4.8.30-13.el7 @epel
libdb4-devel.x86_64 4.8.30-13.el7 @epel
python2-pip.noarch 8.1.2-7.el7 @epel
[root@localhost ~]# yum install -y epel-release # MongoDB包含在EPEL源里面,所以在安装MongoDB必须先安装EPEL源
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package epel-release.noarch 0:7-11 will be reinstalled
--> Finished Dependency Resolution
Dependencies Resolved
==========================================================================================================
Package Arch Version Repository Size
==========================================================================================================
Reinstalling:
epel-release noarch 7-11 extras 15 k
Transaction Summary
==========================================================================================================
Reinstall 1 Package
Total download size: 15 k
Installed size: 24 k
Downloading packages:
epel-release-7-11.noarch.rpm | 15 kB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : epel-release-7-11.noarch 1/1
Verifying : epel-release-7-11.noarch 1/1
Installed:
epel-release.noarch 0:7-11
Complete!
[root@localhost ~]# ls /etc/yum.repos.d/
CentOS-Base.repo epel.repo epel-testing.repo
4.2 安装MongoDB数据库
[root@localhost ~]# yum clean all # 清除yum缓存
Loaded plugins: fastestmirror
Cleaning repos: base code epel extras updates
Cleaning up everything
Maybe you want: rm -rf /var/cache/yum, to also free up space taken by orphaned data from disabled or removed repos
Cleaning up list of fastest mirrors
[root@localhost ~]# yum makecache # 重新生成yum缓存文件
Loaded plugins: fastestmirror
Determining fastest mirrors
epel/x86_64/metalink | 7.3 kB 00:00:00
* epel: mirrors.aliyun.com
base | 3.6 kB 00:00:00
code | 2.9 kB 00:00:00
epel | 4.7 kB 00:00:00
extras | 3.4 kB 00:00:00
updates | 3.4 kB 00:00:00
(1/21): base/7/x86_64/filelists_db | 7.1 MB 00:00:01
(2/21): base/7/x86_64/primary_db | 6.0 MB 00:00:00
(3/21): base/7/x86_64/other_db | 2.6 MB 00:00:00
(4/21): code/primary_db | 40 kB 00:00:00
(5/21): epel/x86_64/group_gz | 88 kB 00:00:00
(6/21): code/filelists_db | 688 kB 00:00:01
(7/21): epel/x86_64/updateinfo | 1.0 MB 00:00:00
(8/21): epel/x86_64/prestodelta | 11 kB 00:00:00
(9/21): code/other_db | 2.2 kB 00:00:00
(10/21): epel/x86_64/primary_db | 6.6 MB 00:00:01
(11/21): extras/7/x86_64/filelists_db | 231 kB 00:00:00
(12/21): extras/7/x86_64/prestodelta | 47 kB 00:00:00
(13/21): extras/7/x86_64/primary_db | 180 kB 00:00:00
(14/21): base/7/x86_64/group_gz | 166 kB 00:00:05
(15/21): updates/7/x86_64/prestodelta | 358 kB 00:00:00
(16/21): updates/7/x86_64/filelists_db | 2.2 MB 00:00:00
(17/21): extras/7/x86_64/other_db | 118 kB 00:00:00
(18/21): updates/7/x86_64/other_db | 351 kB 00:00:00
(19/21): epel/x86_64/other_db | 3.2 MB 00:00:01
(20/21): updates/7/x86_64/primary_db | 2.5 MB 00:00:00
(21/21): epel/x86_64/filelists_db | 11 MB 00:00:10
Metadata Cache Created
[root@localhost ~]# yum install -y mongodb mongodb-server # 安装MongoDB数据库
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* epel: mirrors.aliyun.com
Resolving Dependencies
--> Running transaction check
---> Package mongodb.x86_64 0:2.6.12-6.el7 will be installed
--> Processing Dependency: v8 >= 3.14.5.10 for package: mongodb-2.6.12-6.el7.x86_64
--> Processing Dependency: libboost_filesystem-mt.so.1.53.0()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
--> Processing Dependency: libboost_program_options-mt.so.1.53.0()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
--> Processing Dependency: libpcap.so.1()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
--> Processing Dependency: libstemmer.so.0()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
--> Processing Dependency: libtcmalloc.so.4()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
--> Processing Dependency: libv8.so.3()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
--> Processing Dependency: libyaml-cpp.so.0.5()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
---> Package mongodb-server.x86_64 0:2.6.12-6.el7 will be installed
--> Running transaction check
---> Package boost-filesystem.x86_64 0:1.53.0-27.el7 will be installed
---> Package boost-program-options.x86_64 0:1.53.0-27.el7 will be installed
---> Package gperftools-libs.x86_64 0:2.6.1-1.el7 will be installed
---> Package libpcap.x86_64 14:1.5.3-11.el7 will be installed
---> Package libstemmer.x86_64 0:0-2.585svn.el7 will be installed
---> Package v8.x86_64 1:3.14.5.10-25.el7 will be installed
---> Package yaml-cpp.x86_64 1:0.5.1-1.el7.2 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==========================================================================================================
Package Arch Version Repository Size
==========================================================================================================
Installing:
mongodb x86_64 2.6.12-6.el7 epel 43 M
mongodb-server x86_64 2.6.12-6.el7 epel 6.6 M
Installing for dependencies:
boost-filesystem x86_64 1.53.0-27.el7 base 68 k
boost-program-options x86_64 1.53.0-27.el7 base 156 k
gperftools-libs x86_64 2.6.1-1.el7 base 272 k
libpcap x86_64 14:1.5.3-11.el7 base 138 k
libstemmer x86_64 0-2.585svn.el7 epel 67 k
v8 x86_64 1:3.14.5.10-25.el7 epel 3.0 M
yaml-cpp x86_64 1:0.5.1-1.el7.2 epel 176 k
Transaction Summary
==========================================================================================================
Install 2 Packages (+7 Dependent packages)
Total download size: 54 M
Installed size: 164 M
Downloading packages:
(1/9): boost-filesystem-1.53.0-27.el7.x86_64.rpm | 68 kB 00:00:03
(2/9): boost-program-options-1.53.0-27.el7.x86_64.rpm | 156 kB 00:00:05
(3/9): libpcap-1.5.3-11.el7.x86_64.rpm | 138 kB 00:00:00
(4/9): gperftools-libs-2.6.1-1.el7.x86_64.rpm | 272 kB 00:00:04
(5/9): libstemmer-0-2.585svn.el7.x86_64.rpm | 67 kB 00:00:03
(6/9): mongodb-server-2.6.12-6.el7.x86_64.rpm | 6.6 MB 00:00:01
(7/9): v8-3.14.5.10-25.el7.x86_64.rpm | 3.0 MB 00:00:01
(8/9): yaml-cpp-0.5.1-1.el7.2.x86_64.rpm | 176 kB 00:00:00
(9/9): mongodb-2.6.12-6.el7.x86_64.rpm | 43 MB 00:00:30
----------------------------------------------------------------------------------------------------------
Total 1.5 MB/s | 54 MB 00:00:36
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : boost-filesystem-1.53.0-27.el7.x86_64 1/9
Installing : 1:yaml-cpp-0.5.1-1.el7.2.x86_64 2/9
Installing : boost-program-options-1.53.0-27.el7.x86_64 3/9
Installing : gperftools-libs-2.6.1-1.el7.x86_64 4/9
Installing : 1:v8-3.14.5.10-25.el7.x86_64 5/9
Installing : libstemmer-0-2.585svn.el7.x86_64 6/9
Installing : 14:libpcap-1.5.3-11.el7.x86_64 7/9
Installing : mongodb-2.6.12-6.el7.x86_64 8/9
Installing : mongodb-server-2.6.12-6.el7.x86_64 9/9
Verifying : mongodb-2.6.12-6.el7.x86_64 1/9
Verifying : libstemmer-0-2.585svn.el7.x86_64 2/9
Verifying : 1:v8-3.14.5.10-25.el7.x86_64 3/9
Verifying : gperftools-libs-2.6.1-1.el7.x86_64 4/9
Verifying : boost-program-options-1.53.0-27.el7.x86_64 5/9
Verifying : mongodb-server-2.6.12-6.el7.x86_64 6/9
Verifying : 1:yaml-cpp-0.5.1-1.el7.2.x86_64 7/9
Verifying : boost-filesystem-1.53.0-27.el7.x86_64 8/9
Verifying : 14:libpcap-1.5.3-11.el7.x86_64 9/9
Installed:
mongodb.x86_64 0:2.6.12-6.el7 mongodb-server.x86_64 0:2.6.12-6.el7
Dependency Installed:
boost-filesystem.x86_64 0:1.53.0-27.el7 boost-program-options.x86_64 0:1.53.0-27.el7
gperftools-libs.x86_64 0:2.6.1-1.el7 libpcap.x86_64 14:1.5.3-11.el7
libstemmer.x86_64 0:0-2.585svn.el7 v8.x86_64 1:3.14.5.10-25.el7
yaml-cpp.x86_64 1:0.5.1-1.el7.2
Complete!
4.3 CentOS系统上操作MongoDB数据库常用命令
[root@localhost ~]# systemctl status mongod # 查看系统上MongoDB数据库启动状态
● mongod.service - High-performance, schema-free document-oriented database
Loaded: loaded (/usr/lib/systemd/system/mongod.service; disabled; vendor preset: disabled)
Active: inactive (dead)
[root@localhost ~]# systemctl start mongod # 启动MongoDB数据库
[root@localhost ~]# systemctl status mongod # 再次查看MongoDB数据库的启动状态,显示已启动
● mongod.service - High-performance, schema-free document-oriented database
Loaded: loaded (/usr/lib/systemd/system/mongod.service; disabled; vendor preset: disabled)
Active: active (running) since Mon 2019-03-18 19:22:17 CST; 2s ago
Process: 1393 ExecStart=/usr/bin/mongod $OPTIONS run (code=exited, status=0/SUCCESS)
Main PID: 1395 (mongod)
CGroup: /system.slice/mongod.service
└─1395 /usr/bin/mongod --quiet -f /etc/mongod.conf run
Mar 18 19:22:17 localhost.localdomain systemd[1]: Starting High-performance, schema-free document-or......
Mar 18 19:22:17 localhost.localdomain mongod[1393]: about to fork child process, waiting until serve...ns.
Mar 18 19:22:17 localhost.localdomain mongod[1393]: forked process: 1395
Mar 18 19:22:17 localhost.localdomain systemd[1]: Started High-performance, schema-free document-ori...se.
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost ~]# systemctl stop mongod # 停止MongoDB
[root@localhost ~]# systemctl status mongod
● mongod.service - High-performance, schema-free document-oriented database
Loaded: loaded (/usr/lib/systemd/system/mongod.service; disabled; vendor preset: disabled)
Active: inactive (dead)
Mar 18 19:22:17 localhost.localdomain systemd[1]: Starting High-performance, schema-free document-or......
Mar 18 19:22:17 localhost.localdomain mongod[1393]: about to fork child process, waiting until serve...ns.
Mar 18 19:22:17 localhost.localdomain mongod[1393]: forked process: 1395
Mar 18 19:22:17 localhost.localdomain systemd[1]: Started High-performance, schema-free document-ori...se.
Mar 18 19:22:23 localhost.localdomain systemd[1]: Stopping High-performance, schema-free document-or......
Mar 18 19:22:23 localhost.localdomain systemd[1]: Stopped High-performance, schema-free document-ori...se.
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost ~]# systemctl enable mongod # 把MongoDB设置为开机自启动
Created symlink from /etc/systemd/system/multi-user.target.wants/mongod.service to /usr/lib/systemd/system/mongod.service.
[root@localhost ~]# systemctl disable mongod # 取消MongoDB数据库开机自启动
Removed symlink /etc/systemd/system/multi-user.target.wants/mongod.service.
5.MongoDB的基础命令
数据库基本操作:
show dbs/show databases # 查看所有数据库
use db_name # 切换数据库
db # 查看当前数据库
db.dropDatabase() # 删除当前数据库
命令的基本操作:
db.createCollection(name,options) # 手动创建集合
options可配置选项为:
capped:默认值为false表示集合大小不设置上限,值为true表示为集合大小设置上限
size:当capped值为true时,需要指定参数,表示集合上限大小,当文档达到上限时,会将之前的数据覆盖,单位为字节
show collections # 查看所有集合
db.集合名称.drop() # 删除指定集合
向不存在的集合中第一次加入数据时,集合会自动被创建出来,也可以手动创建集合
示例:
[root@localhost ~]# mongo
MongoDB shell version v3.4.16
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.16
Server has startup warnings:
2019-03-21T21:38:26.752+0800 I CONTROL [initandlisten]
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten]
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten]
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten]
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2019-03-21T21:38:26.753+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2019-03-21T21:38:26.754+0800 I CONTROL [initandlisten]
> show dbs # 查看所有数据库
admin 0.000GB
local 0.000GB
quotes 0.000GB
> db.createCollection("study_test") # 手动创建study_test集合,返回1表示集合创建成功
{ "ok" : 1 }
> use study_test # 使用study_test集合
switched to db study_test
6.MongoDB的数据类型
MongoDB中的数据类型有:
Object ID # 文档ID
String # 字符串,最常用,必须是有效的UTF-8
Boolean # 存储一个布尔值,true或false
Integer # 整数可以是32位或者64位,取决于服务器
Double # 存储浮点值
Arrays # 数组或列表,多个值存储到一个键
Object # 用于嵌入式的文档,即一个值为一个文档
Null # 存储Null值
Timestamp # 时间戳,表示从1970-1-1到现在的总秒数
Date # 存储当前日期或时间的UNIX时间格式
需要注意的点:
1.创建⽇期语句如下 ：参数的格式为YYYY-MM-DD
例如:
> new Date("2018-12-12")
ISODate("2018-12-12T00:00:00Z")
2.每个⽂档都有⼀个
_id属性，保证每个⽂档的唯⼀性.在向集合中写入文档时，可以⾃⼰设置文档的_id属性，如果没有手动指定，则MongoDB会为每个⽂档提供了⼀个唯一的_id， 类型为objectID
objectID是⼀个12字节的⼗六进制数：前4个字节为当前时间戳，接下来3个字节的机器ID，接下来的2个字节中MongoDB的服务进程id，最后3个字节是简单的增量值
例如:
> db.test_table01.insert({"name":"xiaowang","age":10}) # 向test_table01集合中插入一条数据
WriteResult({ "nInserted" : 1 })
> db.test_table01.find() # 打印test_table01中的所有数据
{ "_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"), "name" : "xiaowang", "age" : 10 }
> db.test_table01.find().pretty() # 格式化打印test_table01中的所有数据
{
"_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"),
"name" : "xiaowang",
"age" : 10
}
> db.test_table01.insert({name:"xiaohong",age:20})
WriteResult({ "nInserted" : 1 })
> db.test_table01.find()
{ "_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"), "name" : "xiaowang", "age" : 10 }
{ "_id" : ObjectId("5c939adc4c9ce97c5b78a0db"), "name" : "xiaohong", "age" : 20 }
> db.test_table01.find().pretty()
{
"_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"),
"name" : "xiaowang",
"age" : 10
}
{
"_id" : ObjectId("5c939adc4c9ce97c5b78a0db"),
"name" : "xiaohong",
"age" : 20
}
